The Commonwealth threatened on Monday to suspend Pakistan unless President Pervez Musharraf repealed emergency laws and took other rapid steps to address his country's problems.
The 53-member body, consisting mainly of former British colonies, made the threat at a meeting in London, saying Musharraf must act by Nov 22 to avoid suspension.
The Commonwealth acted as confrontation loomed in Pakistan over a planned protest on Tuesday banned by the authorities but which opposition leader Benazir Bhutto insisted would go ahead.
Police responded to former Prime Minister Bhutto's defiance by serving a week-long detention order on her.
Musharraf set off a storm of criticism when he imposed emergency rule on Nov 3. He suspended the constitution, sacked most judges, locked up lawyers, rounded up thousands of opposition and rights activists and curbed the media.
The crisis in the nuclear-armed country has raised fears about its stability and its focus on battling Islamist militants.
"If after a review of progress Pakistan has failed to implement these necessary measures, it (the Commonwealth) will suspend Pakistan from the councils of the Commonwealth," the body's secretary-general, Don McKinnon, told reporters.
Among the measures demanded were the immediate repeal of emergency laws, the restoration of the constitution, the release of political prisoners, for Musharraf to step down as chief of the army, and for work to progress immediately on holding free and fair elections.
The threat was the latest attempt to put pressure on Musharraf to set Pakistan back on the path to democracy.
In Lahore, a Pakistani government official said earlier that Bhutto would not be allowed to hold the motorcade procession planned for Tuesday from the city of Lahore to protest against emergency rule.
Two-time prime minister Bhutto had urged Pakistanis of all shades to join the motorcade protest against Musharraf's emergency rule and vowed it would go ahead even if police tried to block her.
As darkness fell, hundreds of extra police moved in around the Lahore home of a party official where Bhutto was staying, setting up barricades on streets saying they were for her security. Party officials were not stopped coming and going.
Long march to Islamabad
Bhutto planned to lead a 3-4 day, 270 km "long march" from Lahore to the capital Islamabad to demand Musharraf quit as army chief, end emergency rule, reinstate the constitution and free thousands of detained lawyers and opponents -- including many from her party.
The scene was set for confrontation early on Tuesday when thousands of supporters were expected to converge on the neighbourhood to begin the procession.
"Rallies and protests are banned, they are not allowed," Deputy Information Minister Tariq Azim Khan told Reuters when asked about the protest.
"Whoever breaks the law will be taken to task," he said.
Police have said Bhutto could be the target of a suicide assassination bid, like the one that killed 139 people at a rally last month welcoming her back from eight years in self-exile.
Bhutto, who has for months been in power-sharing talks with Musharraf, said there would be no negotiations while an emergency was in place and the constitution was suspended.
Musharraf justified the emergency by saying the judiciary was hampering the battle against militants and interfering with governance.
Diplomats say his main objective was to stop the Supreme Court from ruling invalid his Oct 6 re-election by legislative assemblies dominated by his supporters.
Musharraf said on Sunday a general election would be held by Jan 9 but declined to say when the emergency would be lifted and the constitution restored.
He also said he would step down as army chief and be sworn in as a civilian president as soon as the Supreme Court, where new judges seen as friendly to the government have been appointed, ruled on challenges to his election.
(Additional reporting by Zeeshan Haider in Islamabad)